Random initialization of arrays is inconsistent

Created by: laurentes

At the C++ level, there are several options to generate random numbers. Across the library, this is currently not consistent: We sometimes rely on blitz++ ranlib, sometimes on boost. In addition, few classes allow the user to set a boost random number generator, whereas others allow him to set a seed.

We have decided to follow this approach:

• Always use boost at the C++ level
• Classes that make use of random numbers should provide a way to set the boost random number generator. We still have to discuss whether it is better to handle the boost random number generator through a reference or a boost::shared_ptr.

The goal is aim to converge to this design. This will involve:

• Make the JFATrainer use boost rather than ranlib
• Remove the seed attribute from:
  • KMeansTrainer
  • PLDABaseTrainer (done by @laurentes)
• Check if we keep using a reference (or a boost::shared_ptr) in the following classes
  • MLP
  • DataShuffler

Please be aware that this will slightly affect the results afterwards, as the initial random matrices will be different